Method of producing lubricating oils



Patented May 5, 1931 PATENT OFFICE UNITED STATES aawm a enema. or roar w'oii'rn, a ms. assmnos. 'ro 'riazaa racrrrc GOAL e OIL 0! FORT WORTH, TEXAS. A GOBPOBATIOH'OF TEXAS METHOD 0! PRODUCING LUIIJCA'IIHG OILS Ho Drawing. Application flea larch 5, This invention relates to a method of producing fully dewaxed, unblended paraflin base lubricating oil of a cold test of approxi' mately 0 F., such as described and claimed as an article of manufacture independent of its process of manufacture in my co ending application, Serial No. 334,607, filed anuary 23, 1929, which is a continuation in part 0 my previous application, Ser. No. 257,110,

filed Feb. 25, 1928, and to the low cold test residual lubricating oil of high viscosity as produced by the processes herein described.

The object of the invention is to provide anprocess or method for the handling of pera n base crude, in this particular instance Ranger crude, as produced in Eastland and Stephens Counties in the State of Texas although applicable to paramn base crude oi from other localities, so as to eflect, during the distilling, refining and purifying operation, the structure of t e paraflin base in the manner which is most favorable for complete removal of the aramn wax constituent, and the reduction 0 a low cold test residual lubrieating oil.

It is gpenerally conceded that .paraifin base oils are st for lubricating oils continue to supply the ing film in automotive en even when the latter are eated up to relatively high de es. Para base oils as heretofore pro need have, however, had the disadvantage of congealing or failin to How at temperatures approaching zero Fa renheit because of the previous impossibility of com mercially fully dewaxin araflin base oils.

I have been able to in ly dewax parallin base lubricating oils and am able to produce a pure fully dewaxed unblended and uncompounded paraffin base oil which will be free flowin at temperatures below its cold test and which, in new of its lubricating roperties at high temperatures as well, can c used for both summer and winter driving conditions or for aeroplane work, eliminating the necessity for producing and marketing two grades of lubricating oil for these difiercnt conditions.

Scientific and performance tests ha e 0 shown that parallin base lubricating oils hav purposes as suc esired lubricat' ace and machines um, Serial its. was.

a lower temperature coeflieient ofviscoswill stand high operating tem eratures halt base oils w ich have a tendency to brea u under high operating temperatures. It is a so recognized that the use of unblended lubricating oils having hydrocarbons in the natural order of their ocing ity better than the as f currence in the crude oil provide a more stable oil, better adapted for use at hi h temperatures than the blended and mixed oils which have constituents vaporizing through a wide range of temperatures.

While my process, in general, observes the same steps and sequence of steps which are normally followed in the refining and purify ing of lubricating oils, I have found that particular care is necessary not only in the disl tilling, but in the refining and dewaxing steps to place or preserve the paraflin or wax base in an amor hous conditionin which the same may be fu 1y removed from the oil prior to placing the same on the market.

In substance, I provide an originally residunl parallin base oil by careful distillation, which contains substantially all amorphous wax and then remove the nsphaltic and tarry h impurities and discolorizingand solid impurities while maintaining the wax in an amorphous condition and t en completely re inove the was from the oil by chilling and dewaxing.

In manufacturin these low cold test fully dewaxed paraflin ase lubricating oils according to my preferred rocess urin the regular process of distillation, gasoline, erosene, gas oils crackin stocks and non-viscous neutrals, etc., are distilled overhead in a continuous battery of stills or in s cially constructed tubular stills equippe with fractionating equipment until in the last still of the continuous battery or in the vacuum tower of the tubular still a lubricating stock of aproaimately to viscosity at 210 15 obtained. During the process of distillation, the stills are kept at a temperature of 20 to 50" lower than in ordinary practice, or at approximately the lower ran e of the boiling or distilling temperature 0 the par ticular traction, using a great amount of bottom steam applied to the oil under low pressure and with a maximum volume. The stills are kept dragging from six {6) to eight (8) hours longer t an in ordinary practice. I have found that this lower tem emture in the distilling operation bringing :1 out a slow distillation with no tendcnc to overheat and no cracking or scorching o the oil prevents the formation of a wax'having a definite crystalline structure and provides in the last still or the long residuum a bright stock of good green color and sweet odor containing substantially all amorphous wax which can be, by the subsequent, steps described below, completely dewaxed if care is observed to maintain the wax in its amorphous condition, whereas crude oil from the same sources, when subjected to a distilling operation in which the stills are maintained at or near the maximum temperature for each particular fraction, often comes from the last still with a crystalline wax formation which subsequently defies complete removal from the oil or when carelessly handled, the amorphous war may be converted into a non'removable variety in the asphalt removal or decolorizing steps.

U on removal from the last still, the brig t stock in my preferred process may be stored and aged from thirty to sixty days at an even temperature in special storage tanks and is then treated in regulation a itators at a temperature of from 115 to l% with a minimum of lbs. per barrel of 98% sulphuric acid. If necessary, the temperature of the oil is reduced, by means of the coolin system, to 115 to 125", or, in winter is raise by suitable heating means. The low temperature at which the oil is subjected to the sulphuric acid or other as halt removal treatment is important as it a acts the oxidization of the parafins in the oil, making it easier to control their proper solidification when chilling. Temperatures above 120 F. in the presence of acid also aflect the solubility of any asphalt bodies in the paralfin, thereby retarding the desired crystalline formation of the parafiin which is necessary for pro er se aration in the production of low col test ubricating oil.

The slud es including tarry and resinous matter pro need by the sulphuric acid treatment are drawn from the agitator and the clean acid oil again pumped to storage where further settling of the sludges is permitted to take place at a storage temperature around 150 F.

The acid oil is then mixed with filtering and dccolorizing clay pulp which has been suitably prepared using .2 pounds or upwards per gallon of nil nnd the mixture of clay pulp and oil is passed through A tulnllur pipe still hcatrrl H1420 F, :il'tr-r vhirh (lulonipnrulurl' i rcllnrnrl tn l lff F. l lunil ulp mixture liluturl with 10% or more oi -hnrl boiling rungc naphtha to rwluro the gm' lly to 36-38 B. and is then forced through a filter, preferably of the pressure type, to separate the clay from the oil. The filtered oil is further diluted with an additional. 30% of naphtha to produce a ravity of 46-48 B., and the mixture is chil ed in special chilling tanks, with special care that the chilling shall be an uninterrupted procedure, reducing the temperature about 2y; every hour until a temperatureof 10 F. above zero is reached. From this point down the oil is chilled as rapidly as possible and held at a minimum temperature of 20 to --40 with agitation, to complete the precipitation of paraflin from solution, so as to permit it to be removed by mechanical means, such as centrifuging or filtering. The mixture is then preferably centrifuged in super centrifu es of the Sharpless type, usin 4 inch fiaed nozzles and a ring size of 41%0 42 which reduces the velocity of the oil being fed to effect a more thorou hly com lete separation of the wax from t e oil. eparation of the solidified wax and the chilled oil ma be effected by passing through a suitable lter. After removal of the wax in this manner, the oil is reclistilled at a low temperature, preferably not exceeding 500 F. with a. considerable amount of low pressure steam to distill 05 the blending naphtha and neutrals, leaving the zero cold test fully dewaxed paralfin base lubricating oil in condition for commercial use.

The oil produced in this manner is a straight=run, unblended, unmixed aralfin base oil with the viscosity of from at 210 F. to 200" at 210 F. Saybolt universal viscosimeter and has a cold test of from 15 below zero or lower to 10 F. It is free flowing at pressures from 7 to 10 pounds even at temperatures as low as minus 40 F. Lubri eating oil of these characteristics has never been produced prior to my production of the same and satisfies in many ways the ideal stn ndard for a universal summer and winter lubricating oil which has been set by the aeroplane and automotive lubrication engineers. Bein a paraflin base lubricating oil, this new 05 provides for better lubrication at high temperatures, and as the oil is unmixed or unblended arafiin base, there are no light ends to distill ofl' or be destroyed by the high temperature. As it is fully de mixed, it is free flowing and can be pumped under normal pump pressures of from 7 to 10 pounds at temperatures even as low as minus 40 F. and therefore provides for proper lubrication at low temperaturesv The process, therefore, produces a lubricating oil which is superior at all temperatures to the n rmal lubricating oils and may he us rl for lmth summer and winter driving and for acroplzun-s in which wide variations in temperaturu are experienced ima relatively short pcriod of time in altitude flights, without the necessity of carrying two grades of oil.

The oil produced has the following characteristics:

1. It is an unblended residuum paraflin base lubricatin oil.

2. It is comp etely dewaxed, i. e., free from wax for commercial purposes.

3. Its viscosity on the Saybolt universal viscosimeter is from at 210 F. to 200" at 210 F. but preferably from 60" at 210 F. to 200" at 210 F.

4. It will flow at pressures from 7 to 10 lbs. absolute at temperatures from plus 20 F. to minus 40 F.

5. It retains its lubricating properties at higher temperatures and being unblended, there is no tendency of any lighter fractions to distill over at higher operating temperatures.

While in general the process I use corres'ponds to conventional commercial processes in the treatment and preparation of lubricating oils, I do not know any process outside the principles of the one disclosed which will result in a completely dewaxed lubricating oil of a viscosity of at 210 up to 160" at 210, nor is it possible with the ordinary run of bright stock to produce a fully dewaxed parafiin base lubricating oil because in the normal distilling operation without special care exercised in my process, the high tem eratures of the still precludes the desire amorphous condition of paraffin and the subsequent treatment with sulphuric acid and subsequent chilling will not convert this wax structure into that desired to permit complete removal of the wax from the oil by any known means.

While I have described my process and the preferred method of erforming the same with considerable detai it will be understood that variations may be made in the specific steps and that the sequence of the steps may be altered without departing from the spirit of my invention or the scope of the appended claims. 0

What I claim as my invention is:

1. The method of producing a fully dewaxed parailin base residual lubricating oil having acold test below 0 F. and a viscosity above 90 at 210 F. from oil from which the lighter fractions have been distilled to provide substantially amorphous wax in the still residue which comprises treating the still residue after aging, with sulphur c acid below 125 F., treating the oil with a decolorizing clay, filtering the clay from the 011, diluting the oil and chilling to 20 to -40 to solidify the wax, separating the solidified wax and removing the diluent from the 011.

2. The method of removing wax from a parafiin base lubricating oil wherein a centrifuge having a #41 to 42 separating ring and 4 inch nozzles is used which comprises treating the still base, from which the lighter fractions have been distilled so that the residue contains wax substantially all of which is in amorphous form, after ageing from 30 to days at an even temperature with a minimum of 35 pounds per barrel of 98% sulphuric acid at 115 to 125 F., removing the acid sludge, reheating the oil with a decolorizing clay, separating the clay from the oil, dilutin the oil, chilling to 20 to 40 F. to soli ify the wax passing the chilled oil through said centri uge to separate the wax from the oil.

3. The method of producing fully dewaxed 0 F. cold test paraflin base residual lubricating oil from crude oil from which the lighter fractions have been distilled at a temperature approximating the lower range of the boiling temperature of the articular fraction to provide a residuum brlght stock of green color and sweet odor, containing amorphous wax and substantially free from crsytalline wax, which would interfere with centrifugal separation of the wax and oil, which comprises ageing the residuum oil, treating the same with sulphuric acid at 115 to 125 F., removing the acid sludge storing the oil to permit settling of the acid sludge, treating the oil with clay at a temperature approximating 420 F., reducing the temperature of the clay and oil to 135 F., diluting the oil with naphtha and filtering to remove the clay further diluting the oil, chilling at a rate approximately 2 per hr. to about 10 F. and chilling more rapidly to 20 to -40 below zero, centrifuging the wax from the oil, and separating the diluent from the dewaxed oil.

4. The method of producing full dewaxed 0 F. cold test parafiin base resi ual lubrieating oil from paraflin base crude oil from which he lighter fractions have been distilled at a temperature approximating the lower range of the boiling temperature of the particular fraction to produce a residual oil containing amorphous wax and substantially free from crystalline wax which comprises ageing the residuum oil, treating the same with sulphuric acid below 125 F., removing the acid sludge, treating the oil with clay below the temperature which would cause conversion of amorphous to crystalline wax, reducing the temperature of the clay and oil, diluting the oil with naphtha and filtering to remove the clay, chilling to from 20 to 40 below zero, removing the wax, and separating the diluent from the dewaxed oil.

5. The method of producing a full dewaxed 0 F. to 10 F. cold test residual ubrieating oil having a viscosity of 50" to 200" at 210 F. from the still residue, or bright stock of parafiin base crude oil which has been distilled to prevent overheating and conversion of amorphous to crystalline wax which,

comprises ageing the still residue, removing the asphaltic and tarry ingredients by sulphuric acid treatment, removing the discoloring material, diluting the oil, chilling to 20 to 40 F. to precipitate the wax, centrifuging the wax from the chilled oil and separating the diluent from the dewaxed oil.

6. The method of producing a full dewaxed parafiin base oil having a col test below 0 F. and viscosity above 90" at 210 from an originally residual undewaxed base containing amorphous wax and substantially free from crystalline wax which comprises removing asphaltic impurities by sulphuric acid treatment while maintaining the wax in an amorphous condition, removing solid and discoloring impurities by clay treatment while maintaining the wax in an amorphous condition, thinning the oil with a solvent, chilling to -20 F. to -40 F. to congeal the wax, separating the congealed wax from the chilled oil and separating the solvent from the dewaxed oil.

7. The method of fully dewaxing paraffin base residual oil which may be partially dewaxed at higher temperatures which comprises providing a residual oil from which the lighter fractions have been distilled so as to provide substantially all amorphous wax in the residue, by ageing the residue, treating with sulphuric acid to remove asphaltic and tarry ingredients, treatin with decolorizing clay, diluting with a lig ter hydrocarbon, chilling to -20 to 40 F. separating the wax from the chilled oil and distilling off the diluent.

8. The below 0 F. cold test dewaxed residual parafiin base lubricating oil, having a viscosity of at 210 F. to 200" at 210 F. roduced from refined still residue from which the lighter fractions have been distilled so as to provide substantially all amorphous wax in the residue by treatment of the residue with sulphuric acid below 125 F., to maintain the wax in an amorphous condition, treatment with decolorizing clay, diluting and chilling to 20 F. to 40 separating the wax from the chilled oil, and separating the diluent from the dewaxed oil.

9. The colddewaxed unblended paraflin base, residual lubricating oil havin a viscosity of from 50 seconds at 210 to 200 seconds at 210 F. on the Saybolt universal viscosimeter and a cold test zero to 10 F. and capable of flowing freely at 7 to 10 lbs. absolute pressure at temperatures as low as -30 F., produced from originally residual cylinder stock containing amorphous wax and substantially free from crystalline wax by treatment with sulphuric acid to remove tarry and asphaltic ingredients, treatment with filter clay to remove discoloring material, dilution of the oil with lighter hydrocarbons, chilling to 30 to 40 F., separating the wax from the chilled oil and separating the diluent from the dewaxed oil.

10. The all season lubricating oil for use in automobile and aero lane engines, comprising an unblended ully dewaxed parafiin base residual oil, having a flash point above 480 F. a Saybolt viscosity above at 210 F. and a cold test below zero F. and being free flowing at pump pressures of 7 to 10 lbs. as low as -40 F., produced from paraffin base crude oil from which the lighter fractions have been distilled at a temperature approximating the lower range of boiling temperature of the particular fraction to provide a still residue containing wax substantially all of which is an amorphous form, by treatment of the still residue with sulphuric acid below 125 F. to remove tarry and asphaltic ingredients, treatment with filter clay to remove discoloring material, dilution of the oil with lighter hydrocarbons, chilling to 30 to 40 F.. separating the wax from the chilled oil and separating the diluent from the dewaxed oil.

11. An all season lubricating oil for uses in automotive engines, comprising an unblended fully dewaxed parafiin base residual oil having a flash point above 480 F. a Saybolt viscosity of from 88" at 210 F. to 155 at 210 F. and a cold test of from zero to 15 F. and being frge flowing at pump pressures of 7 to 10 lbs. as low as 40 F., produced from paraflin base crude oil from which the lighter fractions have been distilled to provide a still residue containing wax substantially all of which is an amorphous form, by treatment of the still residue with sulphuric acid below 125 F. to remove tarry and asphaltic ingredients, treatment with filter clay to remove discoloring material, dilution of the oil with lighter hydrocarbons, chilling to below 20 F., centrifuging the wax from the chilled oil and separating the diluent from the dewaxed oil.

12. Thelow coldtestunblended paraliinbase lubricating oil free of wax, having a viscosity of from 50 seconds at 210 F. to 200 seconds at 210 F. on the Saybolt universal viscosimeter and a cold test of zero to 10 F. prepared from an originally residual stock containing amorphous wax and substantially free from crystalline wax by treatment of the residual stock to remove tarry and asphaltic ingredients while maintaining the wax in an amorphous condition, treatment with filter clay to remove discoloring material while maintaining the wax in an amorphous condition, dilution of the oil with lighter hydrocarbons, chilling to 20 to 40 F., separating the wax from the chilled oil and separating the diluent from the dewaxed oil.

13. The below 0 F. cold test dewaxed unblended parafiin base lubricating oil having a viscosity above 90" at 210 F. produced from an original residual undewaxed base containing amorphous wax and substantially free from crystalline wax by removing the haltic and tarry impurities by sulphuric acid treatment while maintaining the wax in an amorphous condition, iemoving solid and discoloring impurities while maintaining the 5 wax in an amorphous condition, thinnin the oil with a solvent, chilling to --20 to 40 F. to con :11 the wax, separating the congealed wax om the chilled oil and separating the solvent from the dewaxed oil. 10 In testimony whereof I have ailixed my signature to this specification. 4

ERWIN ,R. LEDERER.

7 (Seal) asphaltic and ta impurities by sulphuric acld treatment wh' e maintaining the wax in an amorphous condition, removing solid and discoloring impurities while maintaining the wax in an amorphous condition, thinnin the oil with a solvent, chilling to 20 to 40 F. to con :11 the wax, separating the congealed wax rom the chilled oil and separating the solvent from the dewaxed oil.

In testimony whereof I have aflixed my signature to this specification.

ERWIN R. LEDERER.

QERTIFICATE OF CORRECTION.

Patent No. 1.803.941. Granted my 5, 1931, m

ERWIN R. LEDERER.

. It is hereby certified that error appears the printed specification of the above numbered patent requiring correction as follows: Page 2, line 46, strike outthe word "crystalline"; and that the said Letters Patent should he read with this correction therein that the same may conform to the record of the case in i the Patent Office.

Signed and sealed this 4th day of August, A. D. 1931.

Wm. A. Kinnan, Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 1,803,941. Granted Ma y 5, 1931, to

ERWIN R. LEDERER.

. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 46, strike out the word "crystelline"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 4th day of August, A. D. 1931.

Wm. A. Kinnan, (Seal) Acting Commissioner of Patents. 

